Roentgenographic measurement study for locating femoral insertion site of anterior cruciate ligament: a cadaveric study with X-Caliper

Abstract

The purpose of this study was to determine the relationships of the anterior cruciate ligament (ACL) femoral insertion site with femoral bony landmarks and develop a new method of location. Sixteen unpaired normal Chinese human cadaveric knees were used. Femoral insertion sites of the ACL were marked with metal wires. Four pairs of bony landmarks were selected: anatomical axis of distal femur (A) and parallel tangent of posterior condyles (B); tangent of anterior condyles parallel to landmark A (C) and landmark B; Blumensaat's line (D) and parallel tangent of distal condyles (E); and tangent of posterior condyles (F) and parallel tangent of anterior condyles (G). The X-Caliper was used to measure the distance between the centre of the insertion site and each pair of bony landmarks. The ratio of distances to each pair of bony landmark was calculated. Clock position of the ACL femoral footprint was measured on anteroposterior (AP) roentgenograms at 90 degree flexion. The centre of the ACL footprint was found at 65.3% ± 1.1% between A and B, 78.1% ± 1.0% between B and C, 38.3% ± 2.7% between D and E, and 43.1% ± 4.6% between F and G. The distances to bony landmarks A, B, D, and E have smaller variations. Blumensaat's line and the anatomical axis of the distal femur were regarded as more useful and made location of the insertion site more precise. A parallelogram made up of these two bony landmarks can be used. On AP roentgenograms, the centre of the femoral footprint should be moved to lower than the 10:00 o'clock (2:00) position.

Anatomic Single-Bundle ACL Reconstruction Is Possible with Use of the Modified Transtibial Technique

“…The authors of numerous cadaver studies have attempted to define the anatomic position of ACL footprints where the tunnels should be made (see Appendix) 22,24,[33][34][35][36][37][38] . However, there are discrepancies in the data reported and hence, we tried to create tunnels in the footprints of native ACL insertions without regard to the data of previous studies.…”

Radiographic Anatomy of the Native Anterior Cruciate Ligament: a Systematic Review

“…The percent distances from Blumensaat's line were reported as 27.5% (8 cadaveric knees) [16], 28.5% (10 cadaveric knees) [3], and 38.3% (16 cadaveric knees) [10]. The quantitative synthesis weighted average center point location of the single-bundle analysis was 31.6% from the posterior condyle and 31.5% from Blumensaat's line (see Table 1 and Fig.…”

Radiological evaluation for conflict of the femoral tunnel entrance area prior to anterior cruciate ligament revision surgery

“…-Sagittal plane [18,36] (in percentages) -Axial plane [15] (in degrees on the clock model) -Coronal plane (in degrees on the clock model)…”

“…Several authors have validated radiological measurement methods on lateral plain radiographs for the assessment of tunnel positioning, all of them orientating on the Blumensaat's line [13][14][15][16][17]. The clock model described by Amis et al [16] and further-developed by Sommer et al [14] on tunnel views in 40°of flexion are also frequently used.…”

“…The clock model described by Amis et al [16] and further-developed by Sommer et al [14] on tunnel views in 40°of flexion are also frequently used. Rarely, the same methodology has been applied to anterior-posterior projections in full extension [18][19][20], in tunnel views with 60°of flexion [21] and axial views on CT-scans [15,22].…”